河蟹、青虾、塘鳢混养和单养池塘水质变化比较

Comparison of dynamic water quality among crab shrimp gobbid fish polyculture and crab monoculture system

以河蟹单品种养殖池塘为对照,通过河蟹、青虾和塘鳢混养模式,检测养殖水体水温(WT)、pH值、透明度(SD)、溶解氧(DO)、总氮(TN)、总磷(TP)、化学需氧量(CODMn)和氨氮(NH4+-N)的变化,比较单养各混养模式的水体动态变化及产出效果。结果表明:混养池水温(WT)变化范围为19.1~31.5℃,pH值6.8~7.7,SD 35.0~60.0 cm,DO 5.1~7.6 mg/L,TN 1.53~1.79mg/L,TP 0.135~0.235 mg/L,CODMn7.86~8.59 mg/L,NH4+-N 0.35~0.48 mg/L,符合渔业水质标准(GB11607-89)和国家三类水指标(GB3838-2002)。方差分析结果显示,除水温和pH值外,混养模式与单养模式水质差异性显著。混养池平均纯收益为89 735元/hm2和91 860元/hm2,单养池平均纯收益为65 250元/hm2。混养比单养池多26 610元/hm2。

This experiment established a new cultivation techniques type of polyculture of crab shrimp and gobbid fish. The water-quality index of WT,pH,SD,DO,TN,TP,CODMn. and NH4＋-N during the culture cycle were monitored comparing with the crab monoculture system. The production effects were also valued. Results showed that tile water-quality index of WT ranged from 19.1 to 31.5 ℃,pH value ranged from 6.8 to 7.7,SD ranged from 35 to 60 cm,dissolved oxygen ranged from 5.1 to 7.6 mg/L. TN ranged from 1.53 to 1.79 m^L. TP ranged from 0.135 to 0.235 mg/L,NH4＋-N ranged from 0.35 to 0.48 mg/L. COD ranged from 7.86 to 8.59 mg/L in the poly-eulture system. The water quality in poly-cuhure sections accorded with the demands of ＂Fishery Water Quality Standards＂or ＂Surface Water Quality Standardsm＂,and better than that in the comparison monocuhure system. The ANOVA result of the water indexes showed that difference was very remarkable （P 〈0.05） except waler temperature and pH value. The SD,TN,TP,NH4＋-N,COD were stable in poly-culture ponds,which was more beneficial to aquaculture. The pure income of poly-cuhure system was respectively 89 735 yuan and 91 860 vuan per hectare, and that the net income from crab monoculture system was up to 65 250 yuan per hectare. According analysis of economic benefits,compare with mono-culture group, the poly-culture group raised 26 610 yuan per hectare respectively. Better production results have been achieved in the poly-culture group.